Roshani is standing on a railway bridge which is 140m long He finds that a train crosses the bridge ...........

Quantitative Aptitude (CDS) Problems on trains

Roshani is standing on a railway bridge which is 140m long. He finds that a train crosses the bridge in 16 seconds but himself in 6 seconds. Find the length of the train and its speed?

56.4kmph

54.6kmph

58kmph

60kmph

Explanation:

Let the length of the train be x metres. Then, the train covers x metres in 6 seconds
and (x+140)meters in 16 seconds.
x/6 = (x+140)/16
16x = 6x+ 940
16x - 6x= 940
10x = 940 or x = 94
Length of the train = 94meters
Speed of the train = 94/6 m/sec = (47/3)×18/5 kmph = 56.4kmph